Answer:
D
Explanation:
At constant volume, the heat of reaction is equal to the change in the internal energy of the system. ... Most chemical reactions occur at constant pressure, so enthalpy is more often used to measure heats of reaction than internal energy.
Answer:
CH2O is formaldehyde a covalent compound and its intermolecular forces are week
KCl is an ionic compound formed by electrostatic force of attraction between positive and negative charge. Ionic compounds also exists in three dimensional crystal lattic that is why intermolecular forces in KCl is stronger.
Moreover melting point of KCl is higher than CH2O
Explanation:
NH3 is soluble in water because it has the same amount of intermolecular forces as water. NH3 is a polar molecule and water is a polar molecule so they dissolve each other. NCl3 does not dissolve in water because it is a nonpolar molecule which is different with water. NCl3 is nonpolar due to the difference in electronegativities between 3 atoms of Cl and 1 atom if N2.